The present proposal is intended as both an expansion and renewal of a previously funded research project entitled, "Analysis of A Community-Wide Population of Narcotic Addicts." The previous study investigated, through the use of a three-hour interview and agency record searches, the drug careers of narcotic users first identified as such by the police during the years 1952-1971. From a population of several thousand such individuals 349 males were randomly selected after stratification by race and year of identification. Ninety-eight per cent of these were located, and interviews or death certificates were secured for 93 per cent. In light of the success of that research, the current proposal seeks additional support to enlarge and expand upon that effort through 1) the addition of subjects to the sample for the years 1967-71; 2) the inclusion of subjects identified by police as narcotic users since 1971; 3) the collection of data on the medical and psychological adjustment status of a subsample of the entire study group; and 4) the inclusion of an effort to determine the feasibility of studying the natural children of narcotic abusers. The work detailed in this proposal will build on the previous research by increasing the power and timeliness of the analyses and by adding several new dimensions to the scope of the research.